As unions prepare to fight looser employment code, president could face broad ‘alliance of the aggrieved’

PARIS—As Emmanuel Macron sets out to shake up France’s rigid labor market, the young president is losing the public support he may need to weather protests by the country’s powerful unions.

Less than four months after handing him the presidency in a landslide election win, voters are souring on a leader many hailed as a reformer who would help address Europe’s economic dilemmas and break down traditional ideological divides.